How to Install Local Packages

There are two ways to install npm packages: locally or globally. Choose which kind of installation to use based on how you want to use the package.

• If you want to depend on the package from your own module, using something like Node.js' require, then you want to install locally. This is npm install's default behavior.
• If you want to use a package as a command line tool, (such as grunt CLI), then install it globally.

To learn more about the install command, check out the CLI doc page.

Installing a Package

A package can be downloaded with the command:

> npm install <package_name>

This will create the node_modules directory in your current directory (if one doesn't exist yet) and will download the package to that directory.

Test:

To confirm that npm install worked correctly, check to see that a node_modules directory exists and that it contains a directory for the package(s) you installed.

Example:

Install a package called lodash. Confirm that it ran successfully by listing the contents of the node_modules directory, where you should see a directory called lodash.

Microsoft Windows:

C:\ npm install lodash
C:\ dir node_modules

#=> lodash

macOS, Ubuntu, Debian

> npm install lodash
> ls node_modules             

#=> lodash

Which Version of the Package is Installed?

If there is no package.json file in the local directory, the latest version of the package is installed.

If there is a package.json file, npm installs the latest version that satisfies the semver rule declared in package.json.

Using the Installed Package in Your Code

Once the package is in node_modules, you can use it in your code. For example, if you are creating a Node.js module, you can require it.

Example:

Create a file named index.js, with the following code:

// index.js
var lodash = require('lodash');
 
var output = lodash.without([1, 2, 3], 1);
console.log(output);

Run the code using node index.js. It should output [2, 3].

If you had not properly installed lodash, you would receive this error:

module.js:340
    throw err;
          ^
Error: Cannot find module 'lodash'

To fix this, run npm install lodash in the same directory as your index.js.